diff options
Diffstat (limited to 'chip/g/sps.c')
| -rw-r--r-- | chip/g/sps.c | 51 |
1 files changed, 32 insertions, 19 deletions
diff --git a/chip/g/sps.c b/chip/g/sps.c index b64e1d1a7b..3a44a4fa0e 100644 --- a/chip/g/sps.c +++ b/chip/g/sps.c @@ -310,9 +310,15 @@ static void sps_advance_rx(int port, int data_size) * passed to the callback, the callback is called one last time with zero data * size and the CS indication, this allows the client to delineate received * packets. + * + * Returns a Boolean indicating if data was seen during the most recent CS + * assertion. When 1, it indicates to the caller that the confirmation + * pulse to the AP needs to be generated. */ -static void sps_rx_interrupt(uint32_t port, int cs_deasserted) +static uint32_t sps_rx_interrupt(uint32_t port, int cs_deasserted) { + uint32_t pulse_needed = 0; + for (;;) { uint8_t *received_data = NULL; size_t data_size; @@ -336,30 +342,18 @@ static void sps_rx_interrupt(uint32_t port, int cs_deasserted) if (cs_deasserted) { if (seen_data) { sps_rx_handler(NULL, 0, 1); - - /* - * Signal the AP that this SPI frame processing is - * completed. - */ - gpio_set_level(GPIO_INT_AP_L, 0); - - /* - * This is to meet the AP requirement of minimum 4 usec - * duration of INT_AP_L assertion. - * - * TODO(b/130515803): Ideally, this should be improved - * to support any duration requirement in future. - */ - tick_delay(2); - - gpio_set_level(GPIO_INT_AP_L, 1); seen_data = 0; + pulse_needed = 1; } } + + return pulse_needed; } static void sps_cs_deassert_interrupt(uint32_t port) { + uint32_t pulse_needed; + if (sps_cs_asserted()) { /* * we must have been slow, this is the next CS assertion after @@ -387,7 +381,7 @@ static void sps_cs_deassert_interrupt(uint32_t port) } /* Make sure the receive FIFO is drained. */ - sps_rx_interrupt(port, 1); + pulse_needed = sps_rx_interrupt(port, 1); GWRITE_FIELD(SPS, ISTATE_CLR, CS_DEASSERT, 1); GWRITE_FIELD(SPS, FIFO_CTRL, TXFIFO_EN, 0); @@ -396,6 +390,25 @@ static void sps_cs_deassert_interrupt(uint32_t port) * by clocking out any bytes left over from this one. */ GREG32(SPS, TXFIFO_WPTR) = GREG32(SPS, TXFIFO_RPTR); + + if (pulse_needed) { + /* + * Signal the AP that this SPI frame processing is + * completed. + */ + gpio_set_level(GPIO_INT_AP_L, 0); + + /* + * This is to meet the AP requirement of minimum 4 usec + * duration of INT_AP_L assertion. + * + * TODO(b/130515803): Ideally, this should be improved + * to support any duration requirement in future. + */ + tick_delay(2); + + gpio_set_level(GPIO_INT_AP_L, 1); + } } void _sps0_interrupt(void) |